Extruded open-cell alkenyl aromatic polymer foam and process for making

Abstract

Disclosed is an extruded, open-cell alkenyl aromatic polymer foam useful in insulating applications. The foam has an open cell content of about 30 to about 80 percent. The foam further has in minor dimension and cross-section of greater than 0.25 inches. The foam has a high heat distortion temperature, and is particularly useful in roofing applications. Further disclosed is a process for making the open-cell foam.

What is claimed is: 
     
       1. An extruded, open-cell alkenyl aromatic polymer foam, comprising: a) an alkenyl aromatic polymer material having 90 percent or more by weight alkenyl aromatic monomeric units; and   b) a nucleating agent, the foam having an open-cell content of about 30 to about 80 percent, the foam having a minor dimension in cross-section of greater than 0.25 inches, the foam having a density of about 1.5 pcf to about 6 pcf, the foam having an average cell size of about 0.08 mm to about 1.2 mm, the foam being substantially free of polyphenylene oxide polymers and their derivatives.   
     
     
       2. The foam of claim 1, wherein the foam has a density of about 2.0 pcf to about 3.5 pcf. 
     
     
       3. The foam of claim 1, wherein the foam has an average cell size of about 0.1 mm to about 0.9 mm. 
     
     
       4. The foam of claim 1, wherein the foam has a heat distortion temperature of about 175° F. to about 210° F. 
     
     
       5. The foam of claim 1, wherein the foam has a heat distortion temperature of about 190° F. to about 205° F. 
     
     
       6. The foam of claim 1, wherein the foam is substantially free of rubbery polymer content and thermoset polymer content and polyphenylene oxide polymers and their derivatives. 
     
     
       7. The foam of claim 1, wherein the foam has a minor dimension in cross-section of 0.375 inches or more. 
     
     
       8. The foam of claim 1, wherein the foam has a heat distortion temperature of about 175° F. to about 210° F., the foam being substantially free of C 4-6  diene monomeric content and thermoset polymer content. 
     
     
       9. The foam of claim 1, wherein the foam has a minor dimension in cross-section of 0.375 inches or more, the foam having a density of about 2.0 pcf to about 3.5 pcf, the foam having an average cell size of about 0.1 mm to about 0.9 mm, and the foam having a heat distortion temperature of about 190° F. to about 205° F. the foam being substantially free of C 4-6  diene monomeric content and thermoset polymer content and polyphenylene oxide polymers and their derivatives. 
     
     
       10. An extruded, open-cell alkenyl aromatic polymer foam, comprising: a) an alkenyl aromatic polymer material consisting essentially of polystyrene; and   b) a nucleating agent, the foam having an open-cell content of about 30 to about 80 percent, the foam having a minor dimension in cross-section of greater than 0.25 inches, the foam having a density of about 1.5 pcf to about 6 pcf, the foam having an average cell size of about 0.08 mm to about 1.2 mm, the foam being substantially free of polyphenylene oxide and their derivatives.   
     
     
       11. The foam of claim 10, wherein the foam has a density of about 2.0 pcf to about 3.5 pcf. 
     
     
       12. The foam of claim 10, wherein the foam has an average cell size of about 0.1 mm to about 0.9 mm. 
     
     
       13. The foam of claim 10 wherein the foam has a heat distortion temperature of about 175° F. to about 210° F. 
     
     
       14. The foam of claim 10, wherein the foam has a heat distortion temperature of about 190° F. to about 205° F. 
     
     
       15. The foam of claim 10, wherein the foam is substantially free of rubbery polymer content and thermoset polymer content. 
     
     
       16. The foam of claim 10, wherein the foam has a minor dimension in cross-section of 0.375 inches or more. 
     
     
       17. The foam of claim 10, wherein the foam has a heat distortion temperature of about 175° F. to about 210° F., the foam being substantially free of C 4-6  diene monomeric content and thermoset polymer content. 
     
     
       18. The foam of claim 10, wherein the foam has a minor dimension in cross-section of 0.375 inches or more, the foam having a density of about 2.0 pcf to about 3.5 per, the foam having an average cell size of about 0.1 mm to about 0.9 mm, and the foam having a heat distortion temperature of about 190° F. to about 205° F. the foam being substantially free of C 4-6  diene monomeric content and thermoset polymer content.